Ch. 13: The Blood, Heart and Circulation

What are the functions of the circulatory system

transportation, regulation, and Protection

functions of the circulatory system in regard to transportation is

Respiratory gases, nutrients, and wastes

functions of the circulatory system in regard to regulation is

Hormonal and temperature

functions of the circulatory system in regard to protection is

Clotting and immunity; blood clots, creating a barrier, protecting skin; WBC clean up dead cells

Major components of the Circulatory System are

The Cardiovascular System, and the Lymphatic system

What is the cardiovascular system composed of

Heart: four-chambered pump; Blood vessels: arteries, arterioles, capillaries, venules, and veins

What is the lymphatic system composed of

Lymphatic vessels, lymphoid tissues, lymphatic organs (spleen, thymus, tonsils, lymph nodes)

The average adult blood volume is

5 liters

Arterial blood when leaving the heart is bright red and oxygenated, except for

blood going to the lungs

Venous blood when entering the heart is dark red and deoxygenated except for

blood leaving the lungs

Blood is made out of

45% formed elements and ≈ 55% plasma (by volume)

What are some of the constituents of the blood

Plasma, Albumin, Globulins, and Fibronogen

Characteristics of blood plasma

Fluid part of blood, composed of water, Dissolved solutes

Plasma proteins make up ___of the plasma

7-8%

What does Albumin do

creates osmotic pressure to help draw water from tissues into capillaries to maintain blood volume and pressure

What are the three types of globulins

Alpha, beta, and gamma globulins

What do alpha and beta globulins do

transport lipids and fat-soluble vitamins

What do gamma globulins create

antibodies that function in immunity

What does fibrinogen do

helps in clotting after becoming fibrin

Blood without fibrinogen is called

serum

Regulatory mechanisms maintain plasma volume to maintain

blood pressure

Osmoreceptors in the hypothalamus cause the release of Antidiuretic Hormone from the posterior pituitary gland if

fluid is lost, allowing fluid to be retained

What are the formed elements of blood

Erythrocytes(RBC), Leukocytes(WBC), and Platelets(thrombocytes)

Characteristics of Erythrocytes (Red Blood Cells)

Flattened, biconcave discs; Transport oxygen; Lack nuclei and mitochondria; they carry oxygen to organs of the body, and carbon dioxide to the lungs for expiration.

How many erythrocytes in blood

approximately 5 million/mm3 blood; Have a 120-day life span, Each contain about 280 million hemoglobin molecules

Iron heme is recycled from the

liver and spleen; carried by transferrin (globulin) in the blood to the red bone marrow

Characteristics of leukocytes (White Blood Cells)

Have nuclei and mitochondria, Move in amoeboid fashion

leukocytes Exhibit Chemotaxis which is

the movement directed by attraction to stimulus (seen in clotting)

Leukocytes also exhibit Diapedesis/Extravasation which is

movement through the capillary wall into connective tissue to site of infection/injury

How many leukocytes are in blood

approximately 5000-9000/mm3 blood

What are the types of leukocytes

granular and agranular leukocytes

What is leukocytosis

an increase of the number of white blood cells when we are fighting infections

What is leukemia

many abnormal & immature leukocytes due to cancer of bone marrow

What is Leukopenia

a decrease in white blood cells die to radiation/chemotherapy; an increase in glucocorticoids happens alongside it

What are some kinds of granular leukocytes

neutrophils, eosinophils, and basophils

What are some kinds of agranular leukocytes

monocytes and lymphocytes

What role do lymphocytes have

specific immunity

What role do monocytes have

phagocytosis

What role do basophils have

histamine/ inflammatory response, releases heparin

What role do Eosinophils have

allergy response & parasites

What role do Neutrophils have

they are 1st responders

What are the characteristics of platelets

Smallest formed element, fragments of large cells called megakaryocytic, Lack nuclei, Very short-lived (5−9 days), Clot blood with several other chemicals and fibrinogen,Release serotonin that stimulates vasoconstriction

How many platelets are in blood

approximately 130,000 - 400,000/mm3 blood

What is Hemopoiesis

Process of blood cell formation

What are hematopoietic stem cells

embryonic cells that give rise to all blood cells

Where does hematopoiesis happen

Process occurs in myeloid tissue (red bone marrow) and lymphoid tissue (lymph nodes, spleen, tonsils, thymus); As cells differentiate, they develop membrane receptors for chemical signals

What is erythropoiesis

Formation of red blood cells

Red bone marrow produces about ___RBCs/sec

2.5 million

Regulation of erythropoiesis is stimulated by

erythropoietin (EPO) from the kidneys that respond to low blood O2 levels; Process takes about 3-4 days; Most iron is recycled from old RBCs, the rest comes from the diet Intestinal iron secreted into blood through ferroprotein channels

All iron travels in blood bound to

transferrin

A Major regulator of iron homeostasis is the hormone

hepcidin which removes ferroprotein channels to promote cellular storage of iron and lowers plasma iron levels

What is leukopoiesis

Formation of white blood cells

What are cytokines

signaling molecules used for intercellular communication

Cytokines include

Multipotent growth factor-1; Interleukin-1; Interleukin-3; Granulocyte colony stimulating factor, and Granulocyte-monocyte colony-stimulating factor

Several types of Cytokines stimulate the production of the different

WBC subtypes.

What are antigens

A substance that triggers an immune response.

What are antibodies

A protein produced by the immune system to recognize and neutralize specific antigens.

What is Thrombopoiesis

the production of platelets (thrombocytes) in the bone marrow from hematopoietic stem cells

What does Thrombopoietin (cytokine from liver and kidneys) do

stimulates growth of megakaryocytes

To make a clot intrinsically

Factor XII leads to Factor X>leads phospholipids, calcium ions, and Factor Va, to forms a complex>his complex converts prothrombin into thrombin>Thrombin then converts soluble fibrinogen into insoluble fibrin, which forms a mesh to create a stable blood clot

To make a clot extrinsically

Factor VII leads to Factor X> leads phospholipids, calcium ions, and Factor Va, to forms a complex>his complex converts prothrombin into thrombin>Thrombin then converts soluble fibrinogen into insoluble fibrin, which forms a mesh to create a stable blood clot

What is a Tissue Plasminogen Activator

clot buster!; must be given within 3 hours of CVA onset; activates plasminogen to destroy the clot

Megakaryocytes are large, multinucleated cells that secrete ("bud off")

cell fragments = platelets

What is Hemostasis

cessation of bleeding when a blood vessel is damaged

Damage to blood vessels exposes collagen fibers to blood, producing what

Vasoconstriction, Formation of platelet plug, Formation of fibrin protein web

Intact endothelium secretes prostacyclin (PG12 a prostaglandin) and nitric oxide (NO), which

Vasodilate, and Inhibit platelet aggregation

What does CD39 do

Breaks down ADP into AMP and Pi to inhibit platelet aggregation further

Damaged endothelium exposes collagen leading to

Platelets bind to collagen. Von Willebrand factor (protein produced by endothelial cells) holds them there. Platelets recruit more platelets and form a platelet plug by secreting: (Platelet release reaction); Activated platelets also activate plasma clotting factors

Fibrinogen is converted to fibrin via one of two pathways

instrinsic and extrinsic

How is Fibrinogen is converted to fibrin intrinsically

Activated by exposure to collagen. Factor XII activates a cascade of other blood factors.

How is Fibrinogen is converted to fibrin extrinsically (most direct pathway)

Initiated by tissue thromboplastin (factor III). Next, calcium and phospholipids (from the platelets) convert prothrombin to the active enzyme thrombin, which converts fibrinogen to fibrin.

Vitamin K is needed by the liver to make

several of the required clotting factors; without it, it could lead towards a tendency of excessive bleeding.

What do plasmalogens do

break down blood clots

What is the hematocrit

percentage of red blood cells in whole blood; males typically have more RBC in comparison to women

What is anemia, why does iron deficiency cause anemia

abnormal low hemoglobin or low hematocrit; an iron deficiency impairs the body’s ability to produce red blood cells

What is aplastic anemia

damage to bone marrow

What is Hemolytic Anemia

RBC destruction increases

What is sickle cell anemia

an inherited blood disorder that causes red blood cells to become abnormally shaped (sickle-shaped)

What does Factor XII do

activates kallikrein

What does kallikrein do

activates plasminogen activators like TPA

What do Plasminogen activating factors do

it activates plasminogen into plasmin

What does Thrombin do

it activates fibrinogen into fibrin

What does Plasmin do

dissolves the blood clot

how does the dissolution of clots happen

Factor XII activates Kallikrein > plasminogen > plasmin digests fibrin

Clotting can be prevented with certain drugs including

calcium chelators, heparin, coumadin, and aspirin

What does heparin do

blocks thrombin

What does Coumadin do

inhibit vitamin K

What does Aspirin do

COX Enzyme, inhibits prostaglandin production (TXA2)

What is INR

the relative time it takes for blood to clot

What are the contents of the heart

Four chambers; two upper (atria), two lower (ventricles)

The right atrium receives

deoxygenated blood from the body

The left atrium receives

receives oxygenated blood from the lungs

The right ventricle pumps

deoxygenated blood to the lungs

The left ventricle pumps

oxygenated blood to the body

Fibrous skeleton Separates atria from

ventricles.The atria therefore work as one unit, while the ventricles work as a separate unit.

Pulmonary Circulations happen between the

heart and lungs

Pathway of Pulmonary Circulations

Blood pumps to lungs via pulmonary arteries; Blood returns to heart via pulmonary veins.

Systemic Circulations happen between the

heart and body tissues

Pathway of Systemic Circulations

Blood pumps to body tissues via aorta; Blood returns to heart via superior and inferior venae cavae.

Atrioventricular (AV) valves are located between

the atria and the ventricles including the bicuspid and tricuspid valves